python和c混合编程-cython

  Cython,官方在首页标题就给出了解释，C-Extensions for Python,即python的c扩展。它是一种可以像写python一样轻松地为python语言编写c扩展程序的编程语言，话不多说，用代码解释，哈哈

• 安装cython

  安装cython

  pip install Cython

• cython 的hello world

  创建一个文件，“hello.pyx”,写入代码

  cython hello world

  def say_hello():
      print("hello world!")
  def test_c_define():
      cdef int a = 0
      for i in range(10):
          a += i
      print(a)

  创建文件“setup.py”,写入代码：

  setup.py

  from distutils.core import setup
  from Cython.Build import cythonize
  
  setup(name='Hello world app',
        ext_modules=cythonize("hello.pyx"))

  编译：

  python setup.py build_ext --inplace

  编译成功后，目录下会多处两个文件,hello.c、hello.so,现在进入ipython后可以直接倒入hello模块了
  

  如果觉得手动编译很麻烦，还可以在程序内部导入pyximport模块，具体使用如下：

In [1]: import pyximport; pyximport.install()
Out[1]: (None, <pyximport.pyximport.PyxImporter at 0x111307450>)

In [2]: import hello
/Users/storm/.virtualenvs/py2cpython/lib/python2.7/site-packages/Cython/Compiler/Main.py:367: FutureWarning: Cython directive 'language_level' not set, using 2 for now (Py2). This will change in a later release! File: /Users/storm/Desktop/cpython_test/hello.pyx
  tree = Parsing.p_module(s, pxd, full_module_name)

In [3]: hello.say_hello()
hello world!

In [4]: hello.test_c_define()
45

更多cython语法可以参考官方文档